gpg: Merge two functions in cipher-aead.c

* g10/cipher-aead.c (set_nonce, set_additional_data): Merge into ...
(set_nonce_and_ad): new function.
(write_auth_tag): Print error message here.
(do_flush): Rename var newchunk to finalize.
--

There is no need to have separate functions here.  We should also
print a error message for writing the final tag.

Signed-off-by: Werner Koch <wk@gnupg.org>
This commit is contained in:
Werner Koch 2018-02-28 08:36:46 +01:00
parent 618b86325f
commit 047506a03d
No known key found for this signature in database
GPG Key ID: E3FDFF218E45B72B
1 changed files with 60 additions and 75 deletions

View File

@ -55,49 +55,16 @@ my_iobuf_write (iobuf_t a, const void *buffer, size_t buflen)
}
/* Set the additional data for the current chunk. If FINAL is set the
* final AEAD chunk is processed. */
/* Set the nonce and the additional data for the current chunk. If
* FINAL is set the final AEAD chunk is processed. This also reset
* the encryption machinery so that the handle can be used for a new
* chunk. */
static gpg_error_t
set_additional_data (cipher_filter_context_t *cfx, int final)
{
unsigned char ad[21];
ad[0] = (0xc0 | PKT_ENCRYPTED_AEAD);
ad[1] = 1;
ad[2] = cfx->dek->algo;
ad[3] = cfx->dek->use_aead;
ad[4] = cfx->chunkbyte;
ad[5] = cfx->chunkindex >> 56;
ad[6] = cfx->chunkindex >> 48;
ad[7] = cfx->chunkindex >> 40;
ad[8] = cfx->chunkindex >> 32;
ad[9] = cfx->chunkindex >> 24;
ad[10]= cfx->chunkindex >> 16;
ad[11]= cfx->chunkindex >> 8;
ad[12]= cfx->chunkindex;
if (final)
{
ad[13] = cfx->total >> 56;
ad[14] = cfx->total >> 48;
ad[15] = cfx->total >> 40;
ad[16] = cfx->total >> 32;
ad[17] = cfx->total >> 24;
ad[18] = cfx->total >> 16;
ad[19] = cfx->total >> 8;
ad[20] = cfx->total;
}
if (DBG_CRYPTO)
log_printhex (ad, final? 21 : 13, "authdata:");
return gcry_cipher_authenticate (cfx->cipher_hd, ad, final? 21 : 13);
}
/* Set the nonce. This also reset the encryption machinery so that
* the handle can be used for a new chunk. */
static gpg_error_t
set_nonce (cipher_filter_context_t *cfx)
set_nonce_and_ad (cipher_filter_context_t *cfx, int final)
{
gpg_error_t err;
unsigned char nonce[16];
unsigned char ad[21];
int i;
switch (cfx->dek->use_aead)
@ -127,7 +94,37 @@ set_nonce (cipher_filter_context_t *cfx)
if (DBG_CRYPTO)
log_printhex (nonce, 15, "nonce:");
return gcry_cipher_setiv (cfx->cipher_hd, nonce, i);
err = gcry_cipher_setiv (cfx->cipher_hd, nonce, i);
if (err)
return err;
ad[0] = (0xc0 | PKT_ENCRYPTED_AEAD);
ad[1] = 1;
ad[2] = cfx->dek->algo;
ad[3] = cfx->dek->use_aead;
ad[4] = cfx->chunkbyte;
ad[5] = cfx->chunkindex >> 56;
ad[6] = cfx->chunkindex >> 48;
ad[7] = cfx->chunkindex >> 40;
ad[8] = cfx->chunkindex >> 32;
ad[9] = cfx->chunkindex >> 24;
ad[10]= cfx->chunkindex >> 16;
ad[11]= cfx->chunkindex >> 8;
ad[12]= cfx->chunkindex;
if (final)
{
ad[13] = cfx->total >> 56;
ad[14] = cfx->total >> 48;
ad[15] = cfx->total >> 40;
ad[16] = cfx->total >> 32;
ad[17] = cfx->total >> 24;
ad[18] = cfx->total >> 16;
ad[19] = cfx->total >> 8;
ad[20] = cfx->total;
}
if (DBG_CRYPTO)
log_printhex (ad, final? 21 : 13, "authdata:");
return gcry_cipher_authenticate (cfx->cipher_hd, ad, final? 21 : 13);
}
@ -203,14 +200,9 @@ write_header (cipher_filter_context_t *cfx, iobuf_t a)
if (err)
return err;
err = set_nonce (cfx);
err = set_nonce_and_ad (cfx, 0);
if (err)
return err;
err = set_additional_data (cfx, 0);
if (err)
return err;
cfx->wrote_header = 1;
leave:
@ -233,6 +225,8 @@ write_auth_tag (cipher_filter_context_t *cfx, iobuf_t a)
goto leave;
leave:
if (err)
log_error ("write_auth_tag failed: %s\n", gpg_strerror (err));
return err;
}
@ -247,10 +241,7 @@ write_final_chunk (cipher_filter_context_t *cfx, iobuf_t a)
if (cfx->chunklen)
cfx->chunkindex++;
err = set_nonce (cfx);
if (err)
goto leave;
err = set_additional_data (cfx, 1);
err = set_nonce_and_ad (cfx, 1);
if (err)
goto leave;
@ -273,7 +264,7 @@ static gpg_error_t
do_flush (cipher_filter_context_t *cfx, iobuf_t a, byte *buf, size_t size)
{
gpg_error_t err = 0;
int newchunk = 0;
int finalize = 0;
size_t n;
/* Put the data into a buffer, flush and encrypt as needed. */
@ -289,7 +280,7 @@ do_flush (cipher_filter_context_t *cfx, iobuf_t a, byte *buf, size_t size)
if (cfx->chunklen + cfx->buflen + n >= cfx->chunksize)
{
size_t n1 = cfx->chunksize - (cfx->chunklen + cfx->buflen);
newchunk = 1;
finalize = 1;
if (DBG_FILTER)
log_debug ("chunksize %ju reached;"
" cur buflen=%zu using %zu of %zu\n",
@ -303,20 +294,21 @@ do_flush (cipher_filter_context_t *cfx, iobuf_t a, byte *buf, size_t size)
buf += n;
size -= n;
if (cfx->buflen == cfx->bufsize || newchunk)
if (cfx->buflen == cfx->bufsize || finalize)
{
if (DBG_FILTER)
log_debug ("encrypting: buflen=%zu %s n=%zu\n",
cfx->buflen, newchunk?"(newchunk)":"", n);
if (newchunk)
cfx->buflen, finalize?"(finalize)":"", n);
if (finalize)
gcry_cipher_final (cfx->cipher_hd);
if (!DBG_FILTER)
;
else if (newchunk)
log_printhex (cfx->buffer, cfx->buflen, "plain(1):");
else if (cfx->buflen > 32)
log_printhex (cfx->buffer + cfx->buflen - 32, 32,
"plain(last 32):");
if (DBG_FILTER)
{
if (finalize)
log_printhex (cfx->buffer, cfx->buflen, "plain(1):");
else if (cfx->buflen > 32)
log_printhex (cfx->buffer + cfx->buflen - 32, 32,
"plain(last32):");
}
/* Take care: even with a buflen of zero an encrypt needs to
* be called after gcry_cipher_final and before
@ -324,7 +316,7 @@ do_flush (cipher_filter_context_t *cfx, iobuf_t a, byte *buf, size_t size)
* mode. */
gcry_cipher_encrypt (cfx->cipher_hd, cfx->buffer, cfx->buflen,
NULL, 0);
if (newchunk && DBG_FILTER)
if (finalize && DBG_FILTER)
log_printhex (cfx->buffer, cfx->buflen, "ciphr(1):");
err = my_iobuf_write (a, cfx->buffer, cfx->buflen);
if (err)
@ -333,30 +325,23 @@ do_flush (cipher_filter_context_t *cfx, iobuf_t a, byte *buf, size_t size)
cfx->total += cfx->buflen;
cfx->buflen = 0;
if (newchunk)
if (finalize)
{
if (DBG_FILTER)
log_debug ("chunklen=%ju total=%ju\n",
(uintmax_t)cfx->chunklen, (uintmax_t)cfx->total);
err = write_auth_tag (cfx, a);
if (err)
{
log_error ("gcry_cipher_gettag failed: %s\n",
gpg_strerror (err));
goto leave;
}
goto leave;
if (DBG_FILTER)
log_debug ("starting a new chunk (cur size=%zu)\n", size);
cfx->chunkindex++;
cfx->chunklen = 0;
err = set_nonce (cfx);
err = set_nonce_and_ad (cfx, 0);
if (err)
goto leave;
err = set_additional_data (cfx, 0);
if (err)
goto leave;
newchunk = 0;
finalize = 0;
}
}
}